21808652 has 12 divisors (see below), whose sum is σ = 38885616. Its totient is φ = 10698480.

The previous prime is 21808621. The next prime is 21808681. The reversal of 21808652 is 25680812.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51224 + ... + 51647.

It is an arithmetic number, because the mean of its divisors is an integer number (3240468).

Almost surely, 2^21808652 is an apocalyptic number.

It is an amenable number.

21808652 is a deficient number, since it is larger than the sum of its proper divisors (17076964).

21808652 is a wasteful number, since it uses less digits than its factorization.

21808652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102928 (or 102926 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 21808652 is about 4669.9734474620. The cubic root of 21808652 is about 279.3891957446.

The spelling of 21808652 in words is "twenty-one million, eight hundred eight thousand, six hundred fifty-two".